﻿MeanStar Method
Computes the mean place of a star for J2000.0

Namespace: ASCOM.Astrometry.NOVAS
Assembly: ASCOM.Astrometry (in ASCOM.Astrometry.dll) Version: 6.0.0.0 (6.1.1.2619)

# Syntax

C#
```public short MeanStar(
double tjd,
ref BodyDescription earth,
double ra,
double dec,
ref double mra,
ref double mdec
)```
Visual Basic
```Public Function MeanStar ( _
tjd As Double, _
ByRef earth As BodyDescription, _
ra As Double, _
dec As Double, _
ByRef mra As Double, _
ByRef mdec As Double _
) As Short```
Visual C++
```public:
virtual short MeanStar(
double tjd,
BodyDescription% earth,
double ra,
double dec,
double% mra,
double% mdec
) sealed```

#### Parameters

tjd
Type: System..::..Double
TT (or TDT) Julian date of apparent place.
earth
Type: ASCOM.Astrometry..::..BodyDescription%
Pointer to structure containing the body designation for the Earth
ra
Type: System..::..Double
Apparent right ascension in hours, referred to true equator and equinox of date 'tjd'.
dec
Type: System..::..Double
Apparent declination in degrees, referred to true equator and equinox of date 'tjd'.
mra
Type: System..::..Double%
OUT: Mean right ascension J2000.0 in hours.
mdec
Type: System..::..Double%
OUT: Mean declination J2000.0 in degrees.

#### Return Value

```   0...Everything OK.
1...Iterative process did not converge after 20 iterations.
>10...Error from function 'app_star'.```

# Remarks

Computes the mean place of a star for J2000.0, given its apparent place at date 'tjd'. Proper motion, parallax and radial velocity are assumed to be zero.